The present invention relates to swings for children, and particularly to a motor drive assembly and a frame for use in a child swing. More particularly, the present invention relates to a child swing having a quiet-wind spring motor, seat-swinging escapement mechanism, and run-time indicator that can be mounted in a motor housing supported on a sturdy frame and operated to swing a child seat freely in a smooth arc under the motor housing.
Parents and childcare givers understand only too well that a failing of many conventional child swings driven by wind-up spring motors is that their winding mechanisms often make sharp, loud, ratcheting noises when turned to rewind the spring motor. This is quite a problem since it is a common desire to rewind the spring motor while a child is swinging in the child swing so as to extend the run time of the child swing. The unwelcome "winding" noise produced by conventional child swings often startles, disturbs, and awakens a child that is dozing and swinging in the child swing. A child swing that has a quiet wind and run cycle and therefore operates quietly both during normal swinging and spring motor-winding modes would be a welcomed improvement over conventional child swings.
Another problem with conventional child swings is that it is difficult for a parent or childcare giver to judge how long the swing will continue to run before the spring used to drive the swing unwinds to its fully relaxed position and ceases to impart pendulum motion to the child seat. A new and improved child swing outfitted with an easy-to-use run-time indicator would be well received by parents and childcare givers as it would function to provide advance warning and inform nearby persons as to when it will become necessary to approach the child swing and rewind the spring motor so as to maintain smooth uninterrupted operation of the child swing without disturbing the swinging child seated in the swing.
Many conventional child swings exasperate and frustrate users due to the short running time of the spring motor apparatus used to generate the energy for running the child swing. An improved child swing having an extended running time without adding a lot of expensive motor-drive components and manufacturing costs would avoid the well-known shortcomings of many conventional child swings.
Child swings driven by wind-up spring motors are well known. See, for example, U.S. Pat. Nos. 2,975,866 relating to spring motors; 4,165,872 relating to motor-operated swings; 4,323,233 relating to a pendulum swing including a weighted body that glides up and down one of the support legs of the swing; and 5,083,773 relating to a lobe spring motor for a child's swing. It is also known to use an escapement mechanism in a spring-powered child swing as disclosed in the above-noted patents. Child swings driven by electric motors are also well known. See, for example, U.S. Pat. No. 4,452,446 relating to a battery-operated child's swing and 4,807,872 relating to a child swing with upstanding members in abutting relationships.
Many conventional child swings include frames made of four separate poles that mount separately in a housing to provide four separate side legs. See, for example, U.S. Pat. No. 4,165,872 disclosing a canopy having inner end walls provided with upper and lower leg-engaging portions for mounting four separate inclined supporting legs to the canopy. It would be desirable to provide an improved child swing having only two sturdy U-shaped leg assemblies and a spring motor housing configured to mount on the two sturdy leg assemblies. It would be especially desirable to mount these two sturdy leg assemblies to the spring motor housing in such a way as to permit a user to fold the leg assemblies together to collapse the improved child swing from an "expanded" use position to a "flat" storage position to make it easier to transport and store the child swing when not in use. Many conventional child swings are not easily collapsed to a compact folded position so as to simplify transport and storage and are therefore awkward to handle in crowded living spaces often found at home during typical every day use.
According to the present invention, an improved apparatus is provided for swinging a child seat. The apparatus includes a housing, a swing motor coupled to the housing, and means for connecting a child seat to the swing motor so that the child seat swings relative to the housing in response to operation of the swing motor.
Preferably, the improved apparatus includes a run-time indicator. Illustratively, the swing motor includes a spring and means for winding the spring between a relaxed position and a wound position to store energy in the spring. The run-time indicator provides means for indicating a current position of the spring between its wound and relaxed positions so that the amount of stored energy currently left in the spring is displayed as the swing unwinds during swinging of the child seat. In a preferred embodiment, the housing is formed to include a window, an indicator is positioned in the window, and means is provided for moving the indicator in the window as the spring unwinds between its wound and relaxed positions.
The improved apparatus also preferably includes a pair of U-shaped legs that mount to the housing to provide sturdy support for the housing during swinging of the child seat. The housing is long and hollow and includes a crankshaft extending along its length. Each U-shaped leg includes a horizontal top portion interconnecting vertical spaced-apart first and second side leg portions. Desirably, the top portions are mounted in the housing and oriented to lie along the length of the housing in spaced-apart parallel relation to the crankshaft. By pivotally mounting one or both of the top portions to the housing it is possible to pivot one or both of the U-shaped legs relative to the housing to collapse the improved child swing to a compact state that is easily transported and stored when the swing is not in use.
The improved child swing also preferably includes an improved escapement mechanism for using the energy released by the spring as it unwinds to apply one short push to the child seat during each swing cycle to impart pendulum motion to the child seat. The improved escapement mechanism includes a ratchet wheel coupled to the spring and mounted to rotate on the crankshaft, a drive pawl pivotably connected to a hanger arm of the child seat, and a stop pawl arranged to block rotation of the ratchet wheel to prevent unwinding of the spring during disengagement of the drive pawl and the ratchet wheel. The improved escapement mechanism further includes means for allowing the drive pawl to disengage the ratchet wheel during most of each swing cycle and for ramping the pivotable drive pawl into engagement with the ratchet wheel at the end of one swing stroke of the child seat. Advantageously, such extended disengagement of the drive pawl and the ratchet wheel reduces the volume and continuousness of the noise produced by engagement of a drive pawl and a ratchet wheel during operation of the child swing. Thus, the improved child swing runs longer and more quietly than conventional spring-driven child swings due to its improved escapement mechanism.
Moreover, the improved escapement mechanism in accordance with the present invention is designed to simulate true pendulum movement more closely by positively driving the child seat to maintain swinging motion for only a short time during each swinging cycle and thereby increasing the amount of free-swinging pendulum motion of the child seat during each swinging cycle. Advantageously, this type of drive provides a more swing-like sensation for the child seated in the child seat to provide a more comfortable and relaxing ride.
Also, in preferred embodiments, a one-way clutch is mounted in the ratchet wheel to permit a user to rewind the spring without interrupting swinging movement of the child seat. Illustratively, the one-way clutch is coupled to the spring and mounted on the crankshaft to engage an inner edge of the ratchet wheel. By turning the crankshaft in a spring-winding direction, a user can rotate the one-way clutch (without rotating the ratchet wheel) to wind the spring quietly without disturbing the swinging movement of the child seat or interrupting the operation of the escapement mechanism. Once the rewinding step has been completed, the one-way clutch automatically reestablishes driving engagement with the rotatable ratchet wheel to transmit energy released from the unwinding spring to the escapement mechanism.
Additional objects, features, and advantages of the invention will be apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.